1. Field of the Invention
This invention relates to an improved method for fixing a water-soluble, direct dye to paper.
2. Description of the Prior Art
The paper industry currently recognizes a number of different binders (also known as fixatives or retention aids) useful for binding dyes and pigments to paper, particularly paper tissue and paper toweling. Of these binders, the polyalkylene polyamines, especially polyethylenimine, are generally considered excellent for binding a water-soluble, direct dye to paper. Although such direct dyes are tenaciously bound to paper, some bleeding of these dyes from the paper is usually observed under alkaline conditions, such as in the presence of common household cleaners.
Faessinger, U.S. Pat. No. 3,864,296, teaches an aqueous, low-viscosity, printing fluid, containing a water-soluble, cationic, thermosetting resin and a water-soluble dye which is compatible with the resin in solution. These printing fluids are taught to be useful in high-speed printing processes.